In the Old Testament the English word "consecrate" has been translated from a few different Hebrew words and phrases. The Hebrew word which most closely matches the English word consecrate קדש (qâdash) which has the basic meaning to make clean (Strong's Bible Lexicon).
Another Hebrew expression that was translated into English as consecrate is מלא יד (mâlê' yâd) which means to fill the hand. This expression is found in Exodus 29:9 which reads:
And thou shalt gird them with girdles, Aaron and his sons, and put the bonnets on them: and the priest's office shall be theirs for a perpetual statute: and thou shalt consecrate (fill the hands of) Aaron and his sons.
If Aaron and his sons were to have their hands filled as a part of their priestly duties, what were they to be filled with?
One of the duties of the high priest was to offer incense at certain times, such as on the Day of Atonement (Yom Kippur) as he entered the Holy of Holies (debir). Only the high priest entered the Holy of Holies and he did so only once a year on Yom Kippur. The censer was shaped like a spoon and the priest would use it to scoop up some of the coals off the incense alter in the Holy Place (hekal). He would then pour some incense onto the coals and smoke would fill the temple (see Isaiah 6:1-4 and Revelation 15:8).
Interestingly, the cup portion of the spoon may have had a hand carved on the bottom (see illustration above) so when the Lord instructs Moses to fill the hands of Aaron and his sons this is what he may be referring to.